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SppS. RHIC. FNAL. The Landscape of Particle Production: Results from. SPS. AGS. Peter Steinberg Brookhaven National Laboratory. PHOBOS Collaboration 2004. Birger Back, Mark Baker, Maarten Ballintijn, Donald Barton, Russell Betts, Abigail Bickley ,
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SppS RHIC FNAL The Landscape ofParticle Production:Results from . SPS AGS Peter Steinberg Brookhaven National Laboratory
PHOBOS Collaboration 2004 Birger Back, Mark Baker, Maarten Ballintijn, Donald Barton, Russell Betts, Abigail Bickley, Richard Bindel, Wit Busza (Spokesperson), Alan Carroll, Zhengwei Chai, Patrick Decowski, Edmundo Garcia, Tomasz Gburek, Nigel George, Kristjan Gulbrandsen, Stephen Gushue, Clive Halliwell, Joshua Hamblen, Adam Harrington, Conor Henderson, David Hofman, Richard Hollis, Roman Hołyński, Burt Holzman, Aneta Iordanova, Erik Johnson, Jay Kane, Nazim Khan, Piotr Kulinich, Chia Ming Kuo, Willis Lin, Steven Manly, Alice Mignerey, Gerrit van Nieuwenhuizen, Rachid Nouicer, Andrzej Olszewski, Robert Pak, Inkyu Park, Heinz Pernegger, Corey Reed, Michael Ricci, Christof Roland, Gunther Roland, Joe Sagerer, Iouri Sedykh, Wojtek Skulski, Chadd Smith, Peter Steinberg, George Stephans, Andrei Sukhanov, Marguerite Belt Tonjes, Adam Trzupek, Carla Vale, Siarhei Vaurynovich, Robin Verdier, Gábor Veres, Edward Wenger, Frank Wolfs, Barbara Wosiek, Krzysztof Woźniak, Alan Wuosmaa, Bolek Wysłouch, Jinlong Zhang ARGONNE NATIONAL LABORATORY BROOKHAVEN NATIONAL LABORATORY INSTITUTE OF NUCLEAR PHYSICS, KRAKOW MASSACHUSETTS INSTITUTE OF TECHNOLOGY NATIONAL CENTRAL UNIVERSITY, TAIWAN UNIVERSITY OF ILLINOIS AT CHICAGO UNIVERSITY OF MARYLAND UNIVERSITY OF ROCHESTER
PHOBOS Highlights • d+Au & p+p physics • Multiplicity • Inclusive Spectra • PID • Multiparticle Physics in Au+Au
PHOBOS 2003 TOF & SpecTrig:C. Henderson Trigger & Centrality:R. HollisA. Iordanova PCAL:C. Reed Check out our student posters! Several crucial upgrades for d+Au
Minimum-bias d+Au Predictions as of Oct. 2003 PHOBOS nucl-ex/0311009 See R. Nouicer’s talk
Centrality Dependence of d+Au Data vs. AMPT PHOBOS Preliminary p+p poster by J. Sagerer
Participant Scaling? • Multiplicity extrapolatedto 4p • Relative to p+p multiplicity at same energy, scales with Npart/2 • No modification with • Beam energy • Nuclear thickness
Is Npart Fundamental? Expectations:“stopping” in d direction“cascading” in Au direction Why do they add up toNpart scaling so robustly? Same effect in Au+Au “Long-range” correlation? nucl-ex/0311009
(p)d+Au in Different Frames As with Au+Au, “limiting fragmentation region” grows with energy. Shape appears to be constrained by lower-energy p+A data.Surprising over 1.5 orders of magnitude in collision energy.
Can we build Au+Au with p+p/d+Au? PHOBOS 200 GeV Fundamental differencebetween p+p / d+Au & Au+Au? Au+Au nucl-ex/0301017d+Au & p+p preliminary
Forward Multiparticle Physics in Au+Au h 0 -5 -4 -3 -2 -1 1 2 3 4 5 4p multiplicity measurements show long-range correlation Long-Rangevs.Short-Rangeeffects • Fluctuations & Correlations • HBT Correlations • Azimuthal asymmetries
Forward-Backward Correlations PHOBOS study for Au+Au: • K. Wozniak talk • Correlations consistent w/ UA5 • Weak rapidity dependence from 1<|h|<3 • UA5 p+p: 2-particle clusters explain • Short-range correlations in h • FB correlations UA5 PLB123:361 (1983) PHOBOS Au+Au h 0 -5 -4 -3 -2 -1 1 2 3 4 5
Longitudinal Dynamics with HBT h 0 -5 -4 -3 -2 -1 1 2 3 4 5 See talk by B. Holzman, poster by C.M.Kuo Particles at a givenrapidity are correlatedwith a sourceat the same rapidity Similar to FB result:correlations arelocal in rapidity. PHOBOS Preliminary Au+Au 200 GeV(0.1 < kT < 1.4 GeV/c) Boost Invariant NA49 (1998)(0.1 < kT <0.2 GeV/c) Open symbols reflected Static Source
Directed and Elliptic Flow v2 DirectedFlow y v1p v1p v1p y v1p DirectedFlow UrQMD
Elliptic Flow vs. Centrality See talk by M. Belt Tonjes 200 GeV Open symbols reflected Overall shape simple, but still unexplained
Directed Flow vs. Energy Dramatic change of directed flow near h=0
“Limiting Fragmentation” of v1 PRL91 (2003), Poster by B. Back 19.6 GeV 200 GeV 130 GeV PHOBOS Au+Au Preliminary Similar directed flow relative to beam rapidity
Connection with Net Baryons? BRAHMS, nucl-ex/0312023 Peak of baryon density at AGS/SPS at h’~-1.5 (Busza & Goldhaber ‘84)
Directed & Elliptic Flow b y PHOBOS Preliminary QM2002 200 GeV v2 3-50% 200 GeV v1 6-55%
Ratios with dE/dx PID A “classic” PHOBOS measurement: Two charge signs,two bending directions… …but now we have p+p d+Au Au+Au
Identified Particle Ratios Poster by A. Bickley 200GeV d+Au: nucl-ex/0309013 Au+Au: PRC-R67 (2003) p+p d+Au : No modification (cf. multiplicity) Au+Au: Additional net-baryons near h=0
PHOBOS TOF PID Poster by C. Henderson TOF Walls TOF StartCounter “SpecTrig” SpectrometerTrigger StartCounter See talk by G.Veres Spectrometertrigger enrichedd+Au data set
Particle Ratios at High-pT p p d+Au 200 GeV Main difference between p and p is overall yield. Spectral shape only slightly modified vs. pT
TOF PID Spectra d+Au Pending weak-decay correction
mT Scaling in d+Au and Au+Au Au+Au 200 GeV 20% normalizationat 2 GeV Subm. to PRL nucl-ex/0401006 PossiblemT scalingin d+Au(pendingweak corr.)
Inclusive Charged Hadrons in d+Au h 0 -5 -4 -3 -2 -1 1 2 3 4 5 PHOBOS has a“forward” acceptance(& more in the future!) PRL91, 072302 (2003) Au+Au and d+Auscale differentlyrelative to Ncoll
Spectra in d+Au for h>0 See poster by J. Kane Systematic decrease in Rd+Au with increasing h Saturation of ratio also occurs at a lower pT
h-Dependence of Rd+Au Monotonic evolution from mid-rapidity to forward rapidities.BRAHMS data is a continuation of trends starting at h=0
The Landscape of Particle Production SppS RHIC FNAL SPS AGS • Multiplicity measurements • Npart scaling & limiting fragmentation • Long range correlations in h ? • Forward Multiparticle Physics in Au+Au • FB & HBT show effects local in h for |h|<3 • First measurement of directed flow vs. h & s • Identified Particle Spectra in d+Au • PID Spectra in d+Au, Au+Au for Run-4 • Proton and antiproton spectra similar • Inclusive d+Au Charged Spectra vs. h • Strong h dependence interpolates between h=0 and forward h
Relative Yields vs. pT PHOBOS d+Au 200 GeV
mT Scaling and Strangeness Factor of 2 brings K’s into line (gs ~ 0.5 in pp)
PHOBOS Coverage dN/dh h 0 -5 -4 -3 -2 -1 1 2 3 4 5 Spectrometer Octagon N Rings P Rings Nowhere to hide!
Principal Axes Heavy-ion collisions dominatedby Npart fluctuations Decouple total fromrelative fluctuations Independently partitionedbetween P & N P P+N P – N N (flipping a coin, random walk…)
Forward-Backward Correlations P N h 0 -5 -4 -3 -2 -1 1 2 3 4 5
Simple Exercise Let’s play a game: Shift PYTHIA dN/dyby Dy = 1 Scale up by Npart/2 Recalculate dN/dh Similar shapes (violates energy conservation )
Participant Scaling Wounded Nucleon“Scaling” Transition to d+Au PHOBOS QM ’02